Inflatable personal restraint systems

ABSTRACT

An electronic module assembly (EMA) for use in controlling one or more personal restraint systems. A programmed processor within the EMA is configured to determine when a personal restraint system associated with each seat in a vehicle should be deployed. In addition, the programmed processor is configured to perform a diagnostic self-test to determine if the EMA and the personal restraint systems are operational. In one embodiment, results of the diagnostic self-test routine are displayed on a display included on the electronic module assembly. In an alternative embodiment, the results of the diagnostic self-test routine are transmitted via a wireless transceiver to a remote device. The remote device can include a wireless interrogator or can be a remote computer system such as a cabin management computer system.

CROSS-REFERENCE TO RELATED APPLICATION(S)

The present application claims the benefit of U.S. ProvisionalApplication No. 61/516,681, filed Apr. 5, 2011, titled “AIRCRAFT AIRBAGSWITH WIRELESS DIAGNOSTICS”, which is hereby incorporated by reference inits entirety.

TECHNICAL FIELD

The technology disclosed herein relates generally to safety restraintsystems and to aircraft safety restraint systems in particular.

BACKGROUND

Various types of seat belt and airbag systems have been used to protectpassengers in automobiles, aircraft and other vehicles. In automobiles,airbags typically deploy from the steering column, dashboard, sidepanel, and/or other fixed locations. During a rapid deceleration event(e.g., a collision), a sensor detects the event and transmits acorresponding signal to an initiation device (e.g., a pyrotechnicdevice) on an airbag inflator. Initiation causes the inflator to releasecompressed gas into the airbag via a hose, thereby rapidly inflating theairbag. There are a number of different types of inflators known in theart. Some inflators contain compressed gas (e.g., air, nitrogen, helium,argon, etc.). Other inflators (e.g., gas generating devices) providehigh pressure gas via the chemical reaction of an energetic propellant.

Airbags can be deployed in a number of positions around the vehiclepassenger or driver. Airbags positioned in the steering column, forexample, can inflate in front of the driver to cushion his/her head andtorso from forward impact. Airbags can also be positioned to reduce thelikelihood of whiplash.

Although airbags that deploy from stationary locations (e.g., a steeringcolumn) may be effective in automobiles, they may not be as effective inother types of vehicles having other seating arrangements. Seats incommercial passenger aircraft, for example, can be configured in avariety of layouts that provide different spacing between succeedingrows and adjacent seats. Moreover, such layouts may lack theavailability of stationary structures upon which to mount airbags.Additionally, seatbacks in aircraft may rotate forward and downwardduring a crash or similar event, and thus may be unsuitable for airbagstorage. As a result, airbags have been developed that deploy from seatbelts to accommodate occupants in aircraft and other vehicles. Suchairbags can deploy from, for example, a lap belt and/or a shoulder beltto provide additional protection during a crash or other rapiddeceleration event. Such airbag systems are described in detail in U.S.Pat. No. 5,984,350, which is owned by the assignee of the presentapplication and is incorporated herein in its entirety by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partially schematic isometric view of a personal restraintsystem in accordance with an embodiment of the disclosed technology;

FIG. 2 illustrates how a maintenance worker can check the readiness of anumber of personal restraint systems in an aircraft in accordance withan embodiment of the disclosed technology;

FIG. 3 illustrates an electronic module assembly (EMA) for deploying anumber of personal restraint systems in accordance with an embodiment ofthe disclosed technology;

FIGS. 4A-4C are block electrical diagrams of a circuit for deploying oneor more personal restraint systems and for performing a diagnosticself-check in accordance with an embodiment of the disclosed technology;

FIG. 5 is a block diagram of a handheld wireless interrogator forrecording the results of a diagnostic self-check performed by a numberof EMAs in accordance with an embodiment of the disclosed technology;

FIG. 6 is a flow diagram of steps performed by a programmed processorwithin an EMA to perform a diagnostic self-check in accordance with oneembodiment of the disclosed technology; and

FIG. 7 is a flow diagram of steps performed by a programmed processorwithin an EMA to deploy a personal restraint system in accordance withan embodiment of the disclosed technology.

DETAILED DESCRIPTION

As will explained in further detail below, the disclosed technologyrelates to personal restraint systems for use in vehicles and inparticular for use in aircraft. In one embodiment, the personalrestraint systems are deployed by an electronics module assembly (EMA).The EMA includes a programmed processor and one or more crash sensorsthat are used to deploy one or more of the personal restraint systems.The EMA includes a diagnostic capability to determine the readiness ofthe personal restraint systems to deploy. In one embodiment, the EMAperforms a diagnostic self-test upon manual activation of a button orother control on the EMA. The results of the diagnostic self-test can beindicated on a display on the EMA.

In another embodiment, the EMA includes a wireless transceiver. Arequest to perform a diagnostic self-test is received from a remotedevice via a message received on a wireless communication channel. Theresults of the self-test may be sent back to the remote device with thewireless transceiver. In one embodiment, the remote device is ahand-held, wireless interrogator. In another embodiment, the remotedevice is a cabin management computer system of an aircraft of othercomputer system used to monitor/control the operation of an aircraft orvehicle.

FIG. 1 is a partially schematic isometric view of a seating area in avehicle (e.g., an aircraft) having one or more seats 112 provided withan inflatable personal restraint system 100 (“restraint system 100”)configured in accordance with an embodiment of the present technology.In one aspect of the illustrated embodiment, the seats 112 can be atleast generally similar to conventional seats in, for example, acommercial aircraft. Accordingly, each of the seats 112 includes a backportion 116 extending upwardly from a seat portion 114, and each seat112 is fixedly attached to the floor of the aircraft by a suitable seatmounting structure 118. Although certain embodiments of the presenttechnology are described herein in the context of personal restraintsystems for use in commercial aircraft, those of ordinary skill in theart will appreciate that the various structures and features of thepersonal restraint systems described herein can also be utilized in awide variety of other vehicles, including other aircraft (e.g., privateand military aircraft), ground vehicles (e.g., automobiles, trucks,buses, trains, motor homes), water vehicles, etc.

In another aspect of the illustrated embodiment, the restraint system100 includes an airbag assembly 110 carried on a seat belt 120. Morespecifically, in the illustrated embodiment, the seat belt 120 includesa first web portion 122 a and a corresponding second web portion 122 b.A proximal end portion of the first web portion 122 a can be fixablyattached to the seat mounting structure 118 by means of a hook 128 orother suitable device known in the art. The proximal end portion of thesecond web portion 122 b can be similarly attached to the seat mountingstructure 118 on the opposite side of the seat 112. The distal endportion of the first web portion 122 a carries a connector 126 having atongue portion. The distal end portion of the second web portion 122 bcarries a corresponding buckle 124 configured to receive and releasablyengage the tongue portion of the connector 126 to couple the two webportions 122 a, 122 b together around a seat occupant (not shown) in aconventional manner. In certain embodiments, the connector 126 and thebuckle 124 can be configured to operate in a manner that is at leastgenerally similar to conventional connector/buckle assemblies found onconventional seat belts.

In a further aspect of the illustrated embodiment, the airbag assembly110 includes an airbag 130 that is attached to the first web portion 122a generally proximate the connector 126. In one embodiment, for example,the airbag 130 can be fastened to the first web portion 122 a using themethods and systems disclosed in U.S. patent application Ser. No.13/086,134, which was filed Apr. 13, 2011 and is incorporated herein inits entirety by reference. In FIG. 1, the airbag 130 is illustrated inthe nondeployed configuration in which it is folded neatly and stowedbeneath a flexible and durable cover 132. The cover 132 encloses theairbag 130 and the first web portion 122 a and extends from a back shell127 on the connector 126 to a position adjacent to the hook 128. Thecover 132 includes one or more tear seams (not shown) that are designedto rupture upon airbag inflation enabling the airbag 130 to fullyinflate.

In another aspect of the illustrated embodiment, the airbag assembly 110further includes an inflator hose 140 having a first end portion influid communication with the interior of the airbag 130, and a secondend portion that carries a coupling 142. The coupling 142 is configuredto be operably (e.g., threadably) engaged with an outlet of an airbaginflator 144. Various types of inflators can be used with the airbagsystems described herein. In certain embodiments, the inflator 144 caninclude a stored gas canister that contains compressed gas (e.g.,compressed air, nitrogen, argon, helium, etc.) that can be released uponelectrical initiation of a corresponding pyrotechnic device (e.g., asquib). Suitable inflators can be provided by, for example, Autoliv Inc.of Ogden Technical Center 3350 Airport Road Ogden, Utah, USA 84405. Inother embodiments, other suitable inflator devices can be used withoutdeparting from the scope of the present disclosure. Such inflatordevices can include, for example, gas generator devices that generatehigh pressure gas through a rapid chemical reaction of an energeticpropellant. Accordingly, the present disclosure is not limited to aparticular type of inflator device.

In yet another aspect of the illustrated embodiment, the airbag assembly110 includes a seat belt switch 134 carried on the web connector 126. Inthe illustrated embodiment, the seat belt switch 134 is configured tochange status when the connector 126 is suitably engaged with the buckle124. For example, in one embodiment of the present disclosure, the seatbelt switch 134 can be a “normally closed” switch (e.g., a normallyclosed reed switch) that “opens” when the connector 126 is engaged withthe buckle 124. The opening of the seat belt switch 134 can beeffectuated by a magnet (not shown) carried on the buckle 124. When theconnector 126 is properly engaged with the buckle 124, the seat beltswitch 134 is moved into the field of the magnet, thereby causing theswitch to open.

When the seat belt switch 134 is closed (i.e., when the connector 126 isnot engaged with the buckle 124), the seat belt switch 134 completes acircuit comprised of a pair of wires including a first wire or lead 136a and a second wire or lead 136 b. The first and second wires 136 a, 136b terminate in an electrical connector 138. A second pair of wires 146a, 146 b also terminates in the electrical connector 138. A distal endportion of the second pair of wires 146 carries an electrical connector148 configured to be operably coupled to an ignitor or bridge wire inthe inflator 144. In other embodiments, the seat belt switch 134 can bea “normally open” switch (e.g., a normally open reed switch), that ismagnetically closed when the connector 124 is properly engaged with thebuckle 124.

In a further aspect of the illustrated embodiment, the airbag system 100includes an electronic module assembly (EMA) 150 for controlling thedeployment of the airbag 130 during a rapid deceleration event (e.g., acrash) of sufficient magnitude. The EMA 150 is operably coupled to theairbag assembly 110 via a cable assembly 160. The cable assembly 160includes a first connector 162 that is plugged into the EMA 150 and asecond connector 164 that provides a receptacle for the airbagelectrical connector 138. In the illustrated embodiment, the EMA 150includes a programmed processor 152 that receives electrical power froma power source 154 (e.g., one or more lithium batteries).

In certain embodiments, the cable assembly 160 can include a cable loop166 that completes the circuit from the power source 154 to theprogrammed processor 152 and other components within the EMA. In oneaspect of this embodiment, this approach can conserve a significantportion of battery life because the power source 154 is isolated fromthe processor 152 and other components in the EMA 150 until the cableassembly 160 is plugged into the EMA 150. Therefore, power is not drawnfrom the batteries until the device is installed on the vehicle oraircraft and the cable loop 166 completes the circuit. Though shownschematically, the EMA 150 can include a protective housing thatcontains the various electronics, circuitry, and associated devicescontained within. When employed in, for example, a commercial aircraft,the EMA 150 can be mounted to a rigid structure beneath the seat 112.

In another aspect of the illustrated embodiment, the EMA 150 includes acrash sensor 156 that detects rapid deceleration along a particular axis(e.g., an axis of forward motion of the vehicle). Moreover, in thisembodiment, the crash sensor 156 can include two individual sensorswitches aligned along a common axis for additional safety, as will beexplained below. The sensor switches can be virtually any type ofsuitable switch known in the art for responding to a rapid deceleration(or acceleration) event, including magnetically activated reed switchesand/or hall effect switches.

In operation, if the vehicle experiences a crash or other rapiddeceleration event above a preset magnitude (e.g., greater than 15 g's),the sensor switches in the crash sensor 156 close and complete theircorresponding circuits. One of the sensor switches causes the programmedprocessor 152 to detect the occurrence of a crash event. Upon confirmingthat the seat belt connector 126 is properably engaged with the buckle124 (e.g., by confirming that the seat belt switch 134 is in the “open”position), the programmed processor 152 sends a corresponding signal toa deployment circuit 158. Upon receiving a signal from the programmedprocessor 152, the deployment circuit 158 applies a sufficient voltageto a circuit that includes the ignitor, thereby causing the inflatorassociated with the seat to discharge its compressed gas into the airbag130 via the hose 140. The compressed gas expands and causes the airbag130 to inflate and provides the seat occupant (not shown) withadditional protection during the crash event.

The foregoing discussion provides a high level overview of some of thestructures and functions of the personal restraint system 100 inaccordance with one embodiment of the present technology. Those ofordinary skill in the art will appreciate that various aspects andfeatures of the various subsystems of the personal restraint system 100described above can be utilized in combination with other systemswithout departing from the spirit or scope of the present disclosure.For example, in certain embodiments the airbag assembly 110 describedabove can be used with an EMA that, rather than including a programmedprocessor, can simply include a power source and a crash sensor thatcompletes a circuit to activate an inflator during a crash event.Moreover, those of ordinary skill in the art will appreciate that theEMA 150 of the illustrated embodiment includes a number of othercomponents and features for diagnostics, redundancy, etc., which havenot been described herein to avoid unnecessarily obscuring the generaldescription of various embodiments of the present technology.

Moreover, those of ordinary skill in the art will appreciate thatadditional airbag assemblies 110 (e.g., a second and third airbagassembly or more) can be operably coupled to the EMA 150 for use withthe other seats in the row adjacent to the seat 112. Accordingly, in oneembodiment, if a row of seats in an aircraft includes three seats, eachseat can be outfitted with a seat belt airbag assembly as describedabove, with each of the airbag assemblies coupled to an individualinflator as illustrated in FIG. 1. All three of the airbag assemblies,however, can be initiated by the single EMA 150.

In one embodiment, the crash sensor 156 includes two reed switches thatare aligned along a common axis. In one embodiment, a magnet is orientedso that it is moved by the force of a sudden deceleration oracceleration from a resting position to an active position over the reedswitches. The magnetic field of the crash sensor magnet causes the reedswitches to close and complete circuits within the EMA 150. Because thereed switches in the crash sensor 156 are susceptible to magneticfields, the EMA 150 includes one or more external magnetic field sensors200. The magnetic field sensors are positioned such that they will beactivated by any external magnetic fields that may interfere with theoperation of the crash sensor 156. Such magnetic fields could beproduced by strong magnets of the type found in loudspeakers or thelike.

In another embodiments, the crash sensor 156 can include a pair of reedswitches that are shielded from a fixed magnet by a movable shieldbiased with a spring such as disclosed in U.S. patent application Ser.No. 13/170,179, filed Jun. 27, 2011, and which is herein incorporated byreference.

Because the personal restraint systems remain primed until the momentthey are needed, it is important to periodically test the readiness ofthe systems. Therefore, the EMA includes built-in diagnosticcapabilities. In one embodiment, the programmed processor within the EMA150 tests the capacity of the power supply to deliver the appropriatecurrent required to actuate the ignitors of the personal restraintsystems and to test the integrity of the igniter circuits as well as thecircuitry that detects if a seat belt associated with an airbag assemblyis fastened.

In one embodiment, the EMA 150 includes a diagnostic initiation button204 (FIG. 3) that can be pressed by a technician to initiate adiagnostic routine that is implemented by the programmed processor 152.The results of the diagnostic self-test routine are displayed on anumber of diagnostic indicators 206 (FIG. 3) associated with eachpersonal restraint system and the EMA 150 itself. In one embodiment, thediagnostics indicators 206 comprise single or multicolored LED lightsthat change color and/or illumination patterns (i.e., flashing versuscontinually on etc.) to indicate the results of the diagnostic testroutines. During use, a maintenance technician manually presses thediagnostic test initiation button on each of the EMAs in the aircraftand records the results of the diagnostic test on paper or with anelectronic recording device.

The EMA 150 also includes a wireless transceiver 208 (FIG. 3) that canbe used to receive requests to initiate a diagnostic routine and totransmit the results of the diagnostic routines to the correspondingwireless interrogator that is carried by a maintenance technician who isresponsible for checking the readiness of the personal restraintsystems. Alternatively, the requests to initiate a diagnostic routineand the results of the diagnostic routines can be transmitted via thewireless transceiver 208 to a remote computer system such as the cabinmanagement system (not shown) found on an aircraft.

FIG. 2 illustrates an environmental view of a maintenance technician 254within an aircraft 250 according to an embodiment of the disclosedtechnology. In this embodiment, the technician 254 is tasked withrecording the results of the diagnostic tests performed by each of theEMAs associated with the personal restraint system in each of the seats112. In the embodiment shown, the technician 254 carries a wirelessinterrogator 260 such as a special purpose device or a general purposedevice (laptop computer, tablet computer, smart phone or the like). Theinterrogator 260 sends a signal to each of the EMAs to perform a numberof diagnostic tests and records the results of the diagnostic testsperformed. In one embodiment, each EMA is assigned a uniqueidentification code or serial number that is stored in a non-volatilememory. The wireless interrogator 260 sends a code to the EMA and theEMA having the matching code performs the diagnostic tests and returnsthe results to the wireless interrogator 260.

In one embodiment, testing of the personal restraint systems isperformed at periodic intervals such as every 4,000 flight hours orapproximately once a year. As an alternative to using a wirelessinterrogator 260, the individual EMAs can communicate with one or moreantennas 270 disposed within the aircraft. Each of the antennas 270 isconnected by a wired or wireless connection to a centralized computersystem such as the cabin management system of the aircraft. The cabinmanagement system computer can communicate with each of the EMAs inorder to cause each EMA to perform its diagnostic test routines andreport the results of the diagnostic tests performed. The cabinmanagement system can provide an alert to the crew of the aircraft or toaircraft maintenance personnel that indicates if a personal restraintsystem in any of the seats is not functioning properly.

FIG. 3 illustrates one embodiment of an EMA 150 that contains theelectronic components used to test and deploy a number of personalrestraint systems. In one embodiment, the electronics for the personalrestraint system are mounted on a printed circuit board 300, which isfitted in an enclosure box having a first half 302 and a second upperhalf 304. The printed circuit board 300 supports a number of power cellssuch as lithium batteries 306 and the crash sensor 156 as well as othercomponents. In the embodiment shown, the second half 304 of an enclosurebox includes a domed surface 310 that fits over the crash sensor 156.The domed surface 310 operates to create a physical space betweenobjects that may be positioned against the enclosure box of the EMA. Thesize of the physical space created by the domed surface 310 is selectedto prevent external magnetic fields from interfering with the operationof the crash sensor 156. In one embodiment, the domed surface 310supports the external magnetic field sensors 200. In one embodiment, themagnetic field sensors 200 are secured in supports 312 that are formedon the inner or concave side of the domed surface 310. With the externalmagnetic field sensors secured in the supports 312, the magnetic fieldsensors 200 are positioned within any external magnet field that mayinterfere with operation of the crash sensor 156 and EMA 150. Aconnector 314 is provided on the printed circuit board 300 forconnecting the EMA 150 to a cable assembly that extends to each of thepersonal restraint systems. In the embodiment shown, the EMA ‘150includes an electronic switch that operates as the diagnostic initiationbutton 204 and a number of diagnostic indicators 206, such as LEDs, thatvisually indicate whether the EMA and each of the personal restraintsystems controlled by the EMA is operating properly.

FIGS. 4A-4C are block diagrams of a representative arrangement ofelectronic components within the EMA that operate to deploy the personalrestraint systems. In one embodiment, a programmed processor 152comprises a PIC16F884 microcontroller. Power is supplied to theprogrammed processor from a number of lithium battery cells 154 that areconnected in series. Regulated power is supplied to the programmedprocessor and other circuits from a voltage regulator circuit 320. Thevoltage regulator circuit 320 is configured to receive the batteryvoltage from the battery cells 154 at an input and produces a regulated3.3 volts at an output for use by the programmed processor and awireless transceiver circuit 208.

As indicated above, in one embodiment, the crash sensor 156 comprises apair of magnetically activated reed switches that are aligned along acommon axis. An annular magnet 326 is biased away from the switches by aspring 328. When the crash sensor 156 is exposed a force of the typegenerated during a crash or other rapid deceleration/acceleration, thespring 328 of the crash sensor is compressed by the mass of the annularmagnet 326, thereby allowing the magnet 326 to move over the reedswitches. The magnetic field from the annular magnet 326 causes the reedswitches to change state i.e., to either open or close. In oneembodiment, the switches are closed when the magnet 326 is positionedover the reed switches of the crash sensor 156. In one embodiment, afirst reed switch of the crash sensor is connected between an interruptpin on the programmed processor 152 and ground. When closed by themagnet of the crash sensor, the first reed switch connects the interruptpin to circuit ground in order to signal to the programmed processorthat a crash or other rapid deceleration/acceleration event isoccurring. The other reed switch of the crash sensor 156 is connected inparallel with a 1 kilo-ohm resistor to circuit ground. The second reedswitch functions as a safety mechanism to prevent accidental deploymentof the personal restraint systems as will be described in further detailbelow. The external magnetic field sensors 200 are also connectedbetween circuit ground and separate inputs of the programmed processor152. In one embodiment, each magnetic field sensor includes a reedswitch that changes state when exposed to an external magnetic field.Each switch of the external magnetic field sensors has one terminalconnected to an input of the programmed processor and a second terminalcoupled to circuit ground through a 10 kilo-ohm resistor. The inputs tothe processor 152 coupled to terminals of the external magnetic fieldsensors 200 are tied at +V_(dd). When the switches of the externalmagnetic field sensors 200 are open, the inputs to the programmedprocessor read at the +V_(dd) level and when the switches of theexternal magnetic field sensors 200 are closed, the inputs to theprogrammed processor 152 are grounded.

The programmed processor 152 also has inputs connected to themagnetically activated reed switches found in each of the seat belts.For example, a switch 134 a is in the seat belt for use with seat 1while a switch 134 b is in the seat belt for use with seat 2 and aswitch 134 c is in the seat belt for use with seat 3. One lead wireconnecting to each of the seat switches 134 a-134 c is grounded whileanother wire connecting to the switch is connected to an input on theprogrammed processor 152. A diode protection circuit 340 is providedsuch that each of the lead wires that couple an input of the programmedprocessor 152 to a seat belt switch is connected between a pair ofreverse biased diodes. The cathode side of a first one of the diodes isconnected to the battery voltage and the anode side of the first diodeis connected to the cathode side of a second diode. The anode side ofthe second diode is grounded. As will be appreciated by those skilled inthe art, the voltage on a common node at a point between the diodes towhich the input of the programmed processor is connected is thereforelimited to one diode drop below ground level and one diode drop abovethe battery voltage. The diode protection circuit shields the programmedprocessor from electromagnetic interference (EMI) signals that may beinduced on the lead wires extending to the seat belts. Also connected inparallel with the lead wires to the seat belt switches (i.e between theinputs to the programmed processor and ground) are 100 kilo-ohmresistors.

When the seat belt switches are in their normally closed state, thevoltage supplied to the inputs of the programmed processor is 0 volts orground potential. When the seat belt switches are in the open state, thevoltage at the inputs to the programmed processor 152 rises. Therefore,by reading the voltages on the input pins of the programmed processor,the programmed processor can detect whether the seat belt switches arein the open or closed state. By having the seat belt switches operate ina normally closed manner, the programmed processor can detect an opencircuit in a lead wire and a defective seat belt switch simply bydetecting if the inputs at the programmed processor are grounded whenthe seat belt is not buckled. If a normally open switch were used,additional test steps or leads would be required to differentiatebetween open circuits due to a broken wire or a malfunctioning seat beltswitch.

The lead wires for the switches 134 b and 134 c found in the seat beltsassociated with seats 2 and 3 are connected in the same manner.

To deploy a personal restraint system, the EMA 150 includes a transistorassociated with each inflator. In one embodiment, each ignitor isconnected to a pair of lead wires. One lead wire is coupled to thebattery voltage Vcc, while the second lead is connected to thetransistor 352. For example, ignitor 148 a has one lead wire connectedto Vcc and a second lead wire connected to the drain of transistor 352a. A gate of the transistor 352 a is coupled to an output of theprogrammed processor 152, such that upon application of a suitable logiclevel to the gate, the transistor turns on and allows current to flowthrough the ignitor. When the transistor 352 a is turned on, a currentpath is formed through the igniter or bridge wire between the batteriesto ground. In one embodiment, the application of at least 1.2 amps ofcurrent through the ignitor for 2 milliseconds is required to cause thecorresponding inflator to activate and fill the airbag with gas. In oneembodiment, the source of the transistor 352 a is not connected directlyto ground but is connected through the second reed switch (point 330 inFIGS. 4A-4C), associated with the crash sensor 156 so that current willnot flow through the transistor unless the second reed switch of thecrash sensor 156 is closed. This acts as an additional safety devicesuch that if the programmed processor inadvertently applies a voltagelevel that could turn on the transistor 352 a when the crash sensor 156is not activated, current cannot flow through the ignitor and theinflator will not activate. The ignitors 148 b and 148 c associated withthe inflators for seats 2 and 3 are connected in the same way as theignitor 148 a.

The EMA 150 also includes a second transistor for each personalrestraint system to test the ability of the batteries to deliver asufficient current to the ignitors and to test the integrity of leadwires that connect to the ignitors. To test the personal restraintsystems for seat 1, the EMA includes a transistor 354 a. The source ofthe transistor 354 a is grounded while the drain is connected to a pairof parallely connected resistors 360 that connect to the ignitor. A gateof the transistor 354 a is connected to an output of the processor 152such that upon application of a suitable voltage at the gate, thetransistor 354 a is turned on and current flows through the ignitor andthrough the parallely connected resistors to ground. The currentgenerates a voltage at the resistors that is read at ananalog-to-digital converter input pin of the programmed processor 152.By reading the voltage generated, the processor can determine if theignitor and the lead wires that connect to the ignitor are intact. Thevoltage read should be some predefined percentage of the battery voltagedepending on the relative values of the resistance of the ignitor andthe resistance of the parallely connected resistors. The parallelyconnected resistors also serve to limit the current that flows throughthe ignitor so that the inflator will not activate during a self-testroutine.

To detect if the battery has a sufficient voltage required to actuatethe ignitors, both the transistors 352 a and 354 a are turned off by theprogrammed processor 152 and the voltage on the lead that connects theprogrammed processor to the ignitor is read at an analog-to-digitalconverter input pin. In one embodiment, the analog-to-digital convertercompares the voltage read with the reference voltage Vdd supplied byvoltage regulator 320. In one embodiment, programmed processor 152 isprogrammed to divide Vdd by the digital value of the voltage detectedwhen both transistors 352 and 354 are turned off and to multiply theresult by 1,024. If the ratio is greater than a predefined limit (i.e.,the battery voltage is getting smaller), then an error condition isdetected indicating that the batteries of the EMA 150 should be changed.

The circuits for activating and testing the leads and ignitors for theother personal restraint systems that are controlled by the EMA 150 areconnected in the same manner.

In one embodiment, the EMA circuit 150 includes a wireless transceiver208. In one embodiment, the wireless transceiver 208 is a MRF24J40MA 2.4GHz chip produced by Microchip Corporation. The wireless transceiveroperates to transmit wireless signals via the IEEE 801.15 protocol. Inone embodiment, the wireless transceiver 208 is used to detect signalsfrom a wireless interrogator (e.g., from either a handheld wirelessinterrogator 260 or from a cabin management computer system). Uponreceipt of a wireless signal, the EMA begins performing a diagnosticroutine and reports the results of the diagnostic routine under thecontrol of the programmed processor. The connection and operation of awireless transceiver with the programmed processor 152 is considered tobe well known to those of ordinary skill in the art and need not bediscussed in further detail.

FIG. 5 is a block diagram of the handheld wireless interrogator 260 usedby a maintenance technician or other individual to check the readinessof each of the personal restraint systems in a vehicle.

In one embodiment, the handheld wireless interrogator 260 includes oneor more programmed processors 370 having built-in or externalnon-transitory, read-only memory (ROM) 372 and random access memory(RAM) 374. The read-only memory 372 stores a sequence of programinstructions that cause the handheld wireless interrogator 260 toinstruct each EMA on a vehicle to perform the diagnostic self-tests foreach personal restraint system and records the results of the completeddiagnostic tests. The random access memory 374 may be used to store theresults of the diagnostic tests from each EMA for later delivery toother systems or computers and/or for printing a report.

The programmed processor 370 receives input commands from an inputdevice 378 such as a keypad, touch sensitive screen, buttons, dials orthe like. A display 380 is used by the programmed processor 370 topresent a suitable user interface that instructs an operator how to usethe device and confirms that each EMA has been interrogated. Inaddition, the display can show the results of the diagnostic self-testsperformed by each EMA. If repairs or adjustments need to be made to anindividual personal restraint system, the display can inform thetechnician what maintenance steps should be performed and can keeprecords of the time and date when any maintenance was performed.

In one embodiment, results of the diagnostic self-test routines receivedfrom each EMA are delivered to a remote computer system or other devicevia an input/output port 382. The input/output port may be a USB port,network connection, serial port or the like. The handheld wirelessinterrogator 260 may also include a wireless transmitter/receiver 376that is used to communicate with the EMAs and also to transfer theresults of the diagnostic self-tests performed by each EMA to a remotewireless equipped computer system. The handheld wireless interrogator260 may also include a small printer 384 used to print a hard copy ofthe diagnostic self-test results received from each of the EMAs. Such aprinter may be the type commonly found in credit card point of saledevices or the like. Although not shown, the wireless interrogator 260may also include the appropriate hardware and software to allow thedevice to communicate via other modes such as cellular, Bluetooth or thelike.

Although the wireless interrogator 260 shown in FIG. 5 is described as aspecial purpose device, it will be appreciated that a general purposedevice such a portable computer (laptop, tablet etc.) or other device(smartphone, PDA etc.) with built-in or connected wireless communicationcapability could be used.

FIG. 6 is a flow diagram of steps performed by a programmed processor inan EMA to perform a diagnostic self-test routine. Although the steps areshown and described in a particular order for ease of explanation, itwill be appreciated that the steps could be performed in a differentorder or additional or alternative steps performed in order to achievethe functionality described. In one embodiment, the programmed processorexecutes programmed instructions that are stored on a non-transitory,computer readable media in order to implement the functionalitydescribed.

Beginning at 400, the programmed processor determines if a diagnosticroutine has been requested. Such a request may be received in responseto a service technician activating a switch or pressing a button on theEMA. In another alternative embodiment, the request to initiate adiagnostic self-test is received in a wireless signal that istransmitted from a handheld wireless interrogator device or from anothercomputer system such as a cabin management system, etc. Once a requestto initiate a diagnostic self-test is received, the programmed processordetermines if the battery voltage of the EMA is within an acceptablerange at 402. If the battery voltage is not acceptable, an error isreported at 404. If the battery voltage is acceptable, the processordetermines if the switches in the crash sensor are un-activated (e.g.,are open) at 406. If the crash switches are activated, an error isreported at 408. If the switches of the crash sensor are not activated,the programmed processor determines if the switches of the externalmagnetic field sensors are not activated (e.g., are open) at 410. If oneor both of the switches in the external magnetic field sensors aredetected as being activated (e.g. closed) at step 410, then an error isreported at 412.

Once the battery, crash sensor and external magnetic field sensors havebeen tested, the seat switch and ignitor circuits for each personalrestraint system controlled by the EMA are tested. At 414, the processordetermines if the seat switch in the seat belt is closed. If not, anerror is reported at 416. If the seat switch is closed, the processordetermines at 418 if the ignitor wire has the expected resistance andthe leads to the ignitor are not broken as described above. If theresistance of the ignitor is not as expected, an error is reported at420. If the seat switch and ignitor circuits pass the diagnostic tests,the programmed processor reports a pass condition for the personalrestraint system associated with that particular seat at 422.

At 424, the programmed processor determines if all the personalrestraint systems have been tested. If so, the diagnostic routine forthat particular EMA is complete. If not, the personal restraint systemfor the next seat is tested. As indicated above, the status of thediagnostic self-test routine may be reported by lighting or displayingone or more LEDs in a particular pattern or with a particular color. Forexample the EMA may light a green LED for each seat if the system passesor light a red if the system fails. Alternatively, other cues such asflashing orange LEDS could be used to indicate particular problems suchas low battery voltages, problems with the crash or external magneticfield sensors or problems with the ignitors, etc.

FIG. 7 illustrates steps performed by the programmed processor inaccordance with one embodiment of the disclosed technology to deploy apersonal restraint system in a seat.

Beginning at 450, the programmed processor receives an interrupt signalfrom a crash sensor indicating that a crash or rapiddeceleration/acceleration event has occurred that requires thedeployment of one or more of the personal restraint systems. At 452, theprogrammed processor determines if the switches of the external magneticfield sensors are activated. If the switches of the external magneticsensors have been activated, the programmed processor assumes that anexternal magnetic field is interfering with the crash sensor. An erroris therefore detected and no deployment of the personal restraintdevices is performed at 454. If the external magnetic sensors have notbeen activated by an external magnetic field, then for each seat, theprocessor determines if the seat belt for the associated seat is buckledat 454. If the belt is not buckled, then the personal restraint systemfor that particular seat is not activated. If the seat belt is detectedas being buckled by the opening of the magnetic reed switch in thetongue portion of the buckle, then the ignitor for that particular seatis activated at 456.

At 458, the programmed processor determines if all seats have beenchecked. If so, processing ends at 460. If not, processing returns tothe next seat at 462. Steps 454-458 are then repeated for each seatuntil the personal restraint system for each seat has been deployed ornot deployed depending upon whether the seat belt associated with theseat is buckled or unbuckled.

In one embodiment, seats that do not have their seat belt fastened donot have their personal restraint system deployed. This can act as asafety feature. For example, in some instances, car seats or infantcarriers are secured to a seat with a seat belt. Personal restraintsystems are generally not used when infants or small children are placedin a seat. In such cases, a seat belt extender is used to secure such acar seat or infant carrier to the seat. The seat belt extender does notinclude a magnet in the buckle that will open the reed switch in thetongue portion of the seat belt. Therefore, if a seat belt is detectedas being unbuckled, the programmed processor assumes that either theseat is empty and therefore the personal restraint system need not bedeployed or that a seat belt extender is in use and therefore thepersonal restraint system should not be deployed.

In one embodiment, each EMA enters a periodic sleep mode when notlistening for a diagnostic initiation signal in order to extend thebattery life. In one implementation, each EMA is programmed to wake upfor a short period every five minutes and listen for a code thatindicates a diagnostic check of the EMA's is beginning. The code may bethe aircraft tail number in which the EMA's are installed. Theinterrogator broadcasts this code continuously for five minutes eachtime a diagnostic check of the EMA's is to begin. Each EMA listens forthe code and if detected stays awake for the broadcast of a unique codethat identifies the particular EMA. Upon receipt of the unique code, theEMA performs the diagnostic check and returns the results to theinterrogator. The interrogator then instructs the particular EMA to goback to sleep.

When the last diagnostic check result is received, the interrogator 260broadcasts a “go to sleep” signal that instructs any remaining EMA'sthat are still awake to go back to sleep.

As can be seen from the above description, the disclosed technologyprovides a simple, cost-effective mechanism to control the deployment ofpersonal restraint systems in a vehicle. In addition, the EMA provides asimple mechanism to initiate a diagnostic self-test routine andreporting mechanism for indicating if the personal restraint systemsassociated with the seats are operational. Furthermore, by the use ofwireless technology, each personal restraint system can be easilychecked and repaired if necessary without having to physically inspector manipulate the controls on each EMA.

Embodiments of the subject matter and the operations described in thisspecification can be implemented in digital electronic circuitry, or incomputer software, firmware, or hardware, including the structuresdisclosed in this specification and their structural equivalents, or incombinations of one or more of them. Embodiments of the subject matterdescribed in this specification can be implemented as one or morecomputer programs, i.e., one or more modules of computer programinstructions, encoded on computer storage medium for execution by, or tocontrol the operation of, data processing apparatus.

A computer storage medium can be, or can be included in, acomputer-readable storage device, a computer-readable storage substrate,a random or serial access memory array or device, or a combination ofone or more of them. Moreover, while a computer storage medium is not apropagated signal, a computer storage medium can be a source ordestination of computer program instructions encoded in an artificiallygenerated propagated signal. The computer storage medium also can be, orcan be included in, one or more separate physical components or media(e.g., multiple CDs, disks, or other storage devices). The operationsdescribed in this specification can be implemented as operationsperformed by a data processing apparatus on data stored on one or morecomputer-readable storage devices or received from other sources.

The term “programmed processor” encompasses all kinds of apparatus,devices, and machines for processing data, including by way of example,a programmable microprocessor, microcontrollers, a computer, a system ona chip, or multiple ones, or combinations, of the foregoing. Theapparatus can include special purpose logic circuitry, e.g., an FPGA(field programmable gate array) or an ASIC (application specificintegrated circuit). The apparatus also can include, in addition tohardware, code that creates an execution environment for the computerprogram in question, e.g., code that constitutes processor firmware, aprotocol stack, a database management system, an operating system, across-platform runtime environment, a virtual machine, or a combinationof one or more of them. The apparatus and execution environment canrealize various different computing model infrastructures, such as webservices, distributed computing and grid computing infrastructures.

A computer program (also known as a program, software, softwareapplication, script, or code) can be written in any form of programminglanguage, including compiled or interpreted languages, declarative orprocedural languages, and it can be deployed in any form, including as astand alone program or as a module, component, subroutine, object, orother unit suitable for use in a computing environment. A computerprogram may, but need not, correspond to a file in a file system. Aprogram can be stored in a portion of a file that holds other programsor data (e.g., one or more scripts stored in a markup languagedocument), in a single file dedicated to the program in question, or inmultiple coordinated files (e.g., files that store one or more modules,sub programs, or portions of code). A computer program can be deployedto be executed on one computer or on multiple computers that are locatedat one site or distributed across multiple sites and interconnected by acommunication network.

The processes and logic flows described in this specification can beperformed by one or more programmable processors executing one or morecomputer programs to perform actions by operating on input data andgenerating output. The processes and logic flows can also be performedby, and apparatus can also be implemented as, special purpose logiccircuitry, e.g., an FPGA (field programmable gate array) or an ASIC(application specific integrated circuit).

Processors suitable for the execution of a computer program include, byway of example, both general and special purpose microprocessors, andany one or more processors of any kind of digital computer. Generally, aprocessor will receive instructions and data from a read only memory ora random access memory or both. The essential elements of a computer area processor for performing actions in accordance with instructions andone or more memory devices for storing instructions and data. Generally,a computer will also include, or be operatively coupled to receive datafrom or transfer data to, or both, one or more mass storage devices forstoring data, e.g., magnetic, magneto optical disks, or optical disks.However, a computer need not have such devices. Moreover, a computer canbe embedded in another device, e.g., a mobile telephone, a personaldigital assistant (PDA), a mobile audio or video player, a game console,a Global Positioning System (GPS) receiver, or a portable storage device(e.g., a universal serial bus (USB) flash drive), to name just a few.Devices suitable for storing computer program instructions and datainclude all forms of non volatile memory, media and memory devices,including by way of example semiconductor memory devices, e.g., EPROM,EEPROM, and flash memory devices; magnetic disks, e.g., internal harddisks or removable disks; magneto optical disks; and CD ROM and DVD-ROMdisks. The processor and the memory can be supplemented by, orincorporated in, special purpose logic circuitry.

To provide for interaction with a user, embodiments of the subjectmatter described in this specification can be implemented on a computerhaving a display device, e.g., an LCD (liquid crystal display), LED(light emitting diode), or OLED (organic light emitting diode) monitor,for displaying information to the user and a keyboard and a pointingdevice, e.g., a mouse or a trackball, by which the user can provideinput to the computer. In some implementations, a touch screen can beused to display information and to receive input from a user. Otherkinds of devices can be used to provide for interaction with a user aswell; for example, feedback provided to the user can be any form ofsensory feedback, e.g., visual feedback, auditory feedback, or tactilefeedback; and input from the user can be received in any form, includingacoustic, speech, or tactile input. In addition, a computer can interactwith a user by sending documents to and receiving documents from adevice that is used by the user; for example, by sending web pages to aweb browser on a user's client device in response to requests receivedfrom the web browser.

Embodiments of the subject matter described in this specification can beimplemented in a computing system that includes a back end component,e.g., as a data server, or that includes a middleware component, e.g.,an application server, or that includes a front end component, e.g., aclient computer having a graphical user interface or a web browserthrough which a user can interact with an implementation of the subjectmatter described in this specification, or any combination of one ormore such back end, middleware, or front end components. The componentsof the system can be interconnected by any form or medium of digitaldata communication, e.g., a communication network. Examples ofcommunication networks include a local area network (“LAN”) and a widearea network (“WAN”), an inter-network (e.g., the Internet), andpeer-to-peer networks (e.g., ad hoc peer-to-peer networks).

The computing system can include any number of clients and servers. Aclient and server are generally remote from each other and typicallyinteract through a communication network. The relationship of client andserver arises by virtue of computer programs running on the respectivecomputers and having a client-server relationship to each other. In someembodiments, a server transmits data (e.g., an HTML page) to a clientdevice (e.g., for purposes of displaying data to and receiving userinput from a user interacting with the client device). Data generated atthe client device (e.g., a result of the user interaction) can bereceived from the client device at the server.

From the foregoing, it will be appreciated that specific embodiments ofthe invention have been described herein for purposes of illustration,but that various modifications may be made without deviating from thescope of the invention. Accordingly, the invention is not limited exceptas by the appended claims.

We claim:
 1. An electronic module assembly for controlling thedeployment of one or more personal restraint systems in a vehicle,comprising: a power source for supplying electrical power to one or morepersonal restraint systems; a crash sensor configured to produce anelectronic signal upon exposure to a determined force; a wirelesstransceiver configured to receive instructions to perform one or morediagnostic self-tests a programmed processor configured to executeinstructions to: detect an electronic signal from the crash sensor;deploy one or more of the personal restraint systems upon the detectionof the electronic signal from the crash sensor; wherein the programmedprocessor is further configured to execute instructions to: awaken froma sleep mode; receive a unique code that identifies the electronicmodule assembly; perform one or more diagnostic self-tests on thepersonal restraint systems and on the electronic module assembly todetermine the ability of the electronic module assembly to deploy one ormore of the personal restraint systems and to determine the ability ofthe power source to deploy one or more of the personal restraintsystems; provide results of the one or more diagnostic self-testsperformed; and return to the sleep mode after providing the results. 2.The electronic module assembly of claim 1, wherein the programmedprocessor is configured to transmit the results of the one or morediagnostic self-tests performed to a remote receiver with the wirelesstransceiver.
 3. The electronic module assembly of claim 1, wherein thecrash sensor includes: a switch configured to change state upon exposureto the determined force, wherein the switch is configured such that thepersonal restraint systems do not deploy unless the switch has changedstate.
 4. The electronic module assembly of claim 3, wherein the one ormore personal restraint systems are deployed upon completion of acurrent path through an ignitor and wherein the current path includes asecond switch that is within the crash sensor.
 5. The electronic moduleassembly of claim 1, wherein each of the personal restraint systems ismounted on a seat belt of a vehicle and wherein the seat belt includes aseat belt switch to determine if the seat belt is secured, wherein theprogrammed processor is configured to read a state of the seat beltswitch before deploying a corresponding personal restraint system of theseat.
 6. The electronic module assembly of claim 5, wherein the seatbelt switch is closed when the seat belt is not secured and open whenthe seat belt is secured and wherein the programmed processor isconfigured to detect if the seat belt switch is secured by detecting ifthe seat belt switch is open.
 7. The electronic module assembly of claim1, further comprising a magnetic field sensor that is configured todetect if the electronics module assembly is within an external magneticfield.
 8. The electronic module assembly of claim 7, wherein themagnetic field sensor is a reed switch.
 9. The electronics moduleassembly of claim 1, further comprising: a transistor and resistor inseries with an ignitor hat is configured to deploy the personalrestraint system, wherein the processor is configured to executeinstructions that: turns on the transistor to conduct a current throughthe ignitor and that generates a voltage at the resistor; and reads avoltage on the resistor to determine if the power source has the abilityto deploy the personal restraint system.
 10. A wireless electronicmodule assembly for controlling the deployment of one or more personalrestraint systems in a vehicle, comprising: a power source for supplyingelectrical power to one or more personal restraint systems; a wirelesstransceiver for sending and receiving information to and from a remotedevice; a deployment circuit for deploying one or more of the personalrestraint systems connected to the electronics module assembly; adiagnostic circuit for testing the readiness of one or more of thepersonal restraint systems connected to the electronics module assembly,wherein the diagnostic circuit is configured to test the ability of thepower source to deploy one or more of the personal restraint systems;and a programmed processor configured to execute instructions that causethe programmed processor to: awaken from a sleep mode; receive a uniquecode that identifies the electronic module assembly; receiveinstructions from the remote device to initiate a diagnostic self-testroutine of the electronic module assembly and one or more of thepersonal restraint systems connected to the electronic module assembly;transmit results of the diagnostic self-test routine to the remotedevice with the wireless transceiver; and return to the sleep mode afterproviding the results.
 11. The wireless electronic module of claim 8,further comprising: a memory circuit configured to store a uniqueidentification code, wherein the programmed processor is configured toexecute instructions that cause the programmed processor to: analyzecodes received by the wireless transceiver from the remote device;compare the received codes with a code stored in the memory circuit; andinitiate the diagnostic self-test if the received code matches the codestored in the memory circuit.
 12. The wireless module assembly of claim10, further comprising one or more visual indicators that arecontrollable by the programmed processor to indicate the results of thediagnostic self-test routine.
 13. The wireless electronic moduleassembly of claim 12, wherein the one or more visual indicators arelight emitting diodes.
 14. A wireless interrogation device comprising: awireless transceiver; a programmed processor configured to executeprogram instructions that cause the programmed processor to: transmit acode that identifies an electronics module assembly that controls thedeployment of one or more personal restraint systems in an aircraft;receive diagnostic information from the electronics module assemblyassociated with the code indicating if the associated electronics moduleassembly can deploy the one or more personal restraint systems and if apower source included within the associated electronics module assemblycan deploy one or more personal restraint systems associated with theelectronics module assembly; and transmit a control signal to theelectronics module assembly that causes the electronics module assemblyto enter a sleep mode after receiving the diagnostic information. 15.The wireless interrogation device of claim 14, wherein the wirelessinterrogation device is handheld,
 16. The wireless interrogation deviceof claim 14, wherein the wireless interrogation device is incorporatedinto a cabin management system of an aircraft.
 17. An electronic moduleassembly for controlling the deployment of one or more personalrestraint systems in a vehicle, comprising: a power source; a crashsensor configured to produce an electronic signal upon exposure to adetermined force; a wireless transceiver configured to receiveinstructions to perform one or more diagnostic self-tests a programmedprocessor configured to execute instructions to: detect an electronicsignal from the crash sensor; deploy one or more of the personalrestraint systems upon the detection of the electronic signal from thecrash sensor; wherein the programmed processor is further configured toexecute instructions to: awaken from a sleep mode; receive a unique codethat identifies the electronic module assembly; perform one or morediagnostic self-tests on the electronic module assembly to determine theability of the power source to deploy one or more of the personalrestraint systems; provide results of the one or more diagnosticself-tests performed; and return to the sleep mode after providing theresults.